This invention relates to a drain valve operating device for a cistern of a flush toilet, more particularly, to a lever which controls the opening and shutting of a drain valve of a cistern for flushing a toilet pot. The purpose of the present invention is to allow a choice between flushing a large amount or a small amount of water by turning a lever in either the right or the left direction. Change-over can be effected accurately, and also, the return of the lever to its original position is ensured after operation.
With conventional flush toilets, a change-over lever which controls the draining amount is attached to the cistern for the purpose of adjusting the flushing amount of water according to the nature of evacuation, namely, urine or feces. By operating the lever, the drain valve is opened or shut with the aid of a chain. However, regardless of the direction in which the lever is turned, the degree of opening of the drain valve is constant because the drain valve and the lever joined to the chain are perpendicularly set. Under this arrangement, the amount of flushing water is changed by adjusting the operation angle of the lever. For carrying out this adjustment of the operation angle, notches are made both on a spindle fixing the lever and on a spindle support metal. Through contact of these notched parts, the angle of the lever is regulated in connection with the movement of the lever, namely, according to the direction in which the lever is turned, whereby the lifting degree of the drain valve is adjusted. Thus, in the case of the conventional flush toilet, a great deal of labor is required to assemble such a drain valve operation device which is complicated in structure. There is a resultant higher manufacturing cost.
In view of the above-mentioned disadvantage of the conventional flush toilet, the present invention contemplates to provide a drain valve operating device for a flush toilet which is simple in structure and yet accurate in operation.